Some speaker driver measurements...

While I agree that the SB17NBAC has a much better price/performance ratio, and is probably just as good in the mids as those Textreme Satori, I don't think they are going to be quite as good in the low-end, because of their motor and suspension.
But that's what we are talking about. When you take the low end out of the equation, there's no real reason to pick the Satori over the NAC/NBAC.
 
Like this one?
SB Acoustics SB17CRC35-4 | HiFiCompass

That dip at 1500Hz or so is usually a result of the half-roll surround, and it exists on-axis too. At some frequency the surround starts operating out of phase with the cone, causing some cancellation. The surround construction here has a lot to do with it, it's common in many speakers, not just SB. The wavy pro-style surround help here, or something extra crazy like what Purifi does or some Fostex models had complex surround construction to combat the effect.

The good news is that the dip is short band, and won't offended since it's a dip rather than a peak. People usually aren't put off by what they don't hear.
 
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I did think it would be the surround/edge resonance almost immediately after posting, but the more important part I forgot to put in would be how to address the edge resonance. Cone reinforcement or injecting the surround with damping material?
And yes it is common, but the SB units are otherwise more well-behaved than most others in the midband that it stands out.
In any case, the off-axis dip limits convenient x-over transition wrt directivity. In that case, the Textreme behaves too much like the NAC cone as measured instead of the datasheet, which seemed a little poorly fit as a midrange driver.
 
The dip between 1-2 kHz is not the surround, it's a cone (edge?) flexing resonance of the soft cone, the hard cones doesn't have this behavior. Easy to see with comparison, just check the alu vs paper from the same driver family, everything is the same except the cone, hard vs soft, same as with SEAS (alu vs paper) drivers.
 
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Yes, in my view, this 1.2k dip is a compound of edge resonance that affects not-so- rigid cones.

The suck-out in directivity aspect is interesting, i think it comes down to cone geommetry and dust cap.
For sure there are not that many drivers with a similarly-shaped relatively deep concave cone with no dust cap. Only ones I think of off-hand are some Accutons... perhaps their measurements might show some similar effects?
 
Indeed it does. I replied earlier in one of the threads about mw16tx that problems with fr off axis vs ordinary Satori are most obviously due to cone shape. For me personally it's a weird design choice for a transducer that should be intended to be crossed around 3kHz... unless due to 5kHz resonance it's not. Atm driver looks very good, but it's usability is questionable. Maybe it'll work with Satori TW29bnwg though, and that'll be top drawer pairing.
 
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Definitely, and Hificompass website has a special place for me as it allows full screen visualization for fast and accurate comparison across drivers:

  1. I open 2 hificompass measurements of the drivers I want to compare. (2 windows, not 2 tabs)
  2. I look for a voltage giving me the same SPL in case I m comparing 4 Vs 8ohms or too different sensitivity drivers.
  3. I can instantly switch via [alt+Tab] across tabs with a given measurement in full screen
  4. I use left and right arrow to switch across levels/measurements within the same section
  5. Bliss
Are you using it the same way?
 
Hahaha ! I did not even realise it was him. I am looking stupid now :drunk:

Anyway, I think that, just like Amirm and Hificompass, Erin's tests and reviews are some of the best things happening in the audio world right now, wherever I read/watch them :cheers:

i very much like dibirama also, far from the in depth detailed measurements as hificompass or erins but i like the presentation and the number of tested drivers

diBirama italian diy loudspeakers, autocostruzione, Diego Sartori
 
Thanks Mr. K!

Seems like top performance across the board except for the disappointing IMD and low-end. What are your thoughts on its audibility, and do you think the IMD would be an issue if the Xmax were kept to 1 mm or below (same test conditions as in your review)?

For me, it doesn't seem like it beats the Purifi as the bottom of a 2-way, but could make for a really nice low-midrange in a 3-way or 4-way.
Personally, I don't suffer from IMD when listening to the music, but not to the test signals, so, I don't think the IMD would be a problem when keeping the excursion below of 1 mm too. The 2nd harmonic distortion puts much more to a sound signature. I'm sure there will be a persons who much more sensitive to the IMD distortion and have another opinion. It's all too subjective.
No one speaker for a while has surpassed the low frequency IMD distortion capabilities of Purifi...:)